The yeast CCR4 protein is required for the expression of a number of genes involved in nonfermentative growth, including glucose-repressible ADH2, and is the only known suppressor of mutations in the SPT6 and SPT10 genes, two genes which are believed to be involved in chromatin maintenance. We show here that although CCR4 did not bind DNA under the conditions tested, it was able to activate transcription when fused to a heterologous DNA-binding domain. The transcriptional activation ability of CCR4, in contrast to that of many other activators, was glucose regulated. Two activation domains one of which was glucose responsive and encompassed a glutamine-proline-rich region similar to that found in other eukaryotic transcriptional factors were identified. The two transactivation regions, when separated from the leucine-rich repeat and the C terminus of CCR4, were unable to complement a defective ccr4 allele, suggesting that the leucine-rich repeat and the C terminus make contacts that link the activation regions to the proper gene context. Native immunoprecipitation of CCR4 revealed that CCR4 was complexed with at least four other proteins. The leucine-rich repeat of CCR4 was both necessary and sufficient for interaction with at least two of these factors. We propose that the leucine-rich repeat links CCR4 through its associated factors to its promoter context at ADH2 and other loci where it is required for proper transcriptional regulation.The general transcription factor CCR4 from Saccharomyces cerevisiae is required for the transcription of a number of genes involved in nonfermentative growth, including that of the ADH2 gene (encoding the glucose-repressible alcohol dehydrogenase II) (11). Strains containing a deletion of CCR4 also fail to grow at elevated temperatures on a nonfermentative medium, consistent with the global role played by CCR4 under these growth conditions (14). Cells lacking CCR4, however, display other phenotypes, suggesting that CCR4 is involved in processes in addition to that of controlling nonfermentative growth. ccr4 mutations display a cold sensitivity phenotype under glucose growth conditions, a phenotype observed for defects in transcription initiation complex factors such as TFIIB, RPB1, SRB2, and SRB4 (1,2,29,30,33,34,37,41). In addition, CCR4 is required for the elevated expression at the ADH2 locus and for the altered transcriptional initiation at the his4-9128 locus that results from defects in the SPT6 and SPT10 genes (14). The SPT6 and SPT10 genes encode factors that are responsible for maintaining proper transcriptional control over a wide range of genes, and SPT6 has been specifically implicated in the maintenance of chromatin structure (11,26,27,39,40). spt6 mutations, moreover, suppress defects in the global transactivators SNF2 and SNF5, which are known to be involved in maintaining proper nucleosome positioning (5,6,19,28,43 known suppressor of spt6, may be functioning to counteract the repressive effects that SPT6 has on chromatin structure. CCR4 is also required for ADR...

The yeast CCR4 protein is required for the expression of a number of genes involved in nonfermentative growth, including glucose-repressible ADH2, and is the only known suppressor of mutations in the SPT6 and SPT10 genes, two genes which are believed to be involved in chromatin maintenance. We show here that although CCR4 did not bind DNA under the conditions tested, it was able to activate transcription when fused to a heterologous DNA-binding domain. The transcriptional activation ability of CCR4, in contrast to that of many other activators, was glucose regulated. Two activation domains one of which was glucose responsive and encompassed a glutamine-proline-rich region similar to that found in other eukaryotic transcriptional factors were identified. The two transactivation regions, when separated from the leucine-rich repeat and the C terminus of CCR4, were unable to complement a defective ccr4 allele, suggesting that the leucine-rich repeat and the C terminus make contacts that link the activation regions to the proper gene context. Native immunoprecipitation of CCR4 revealed that CCR4 was complexed with at least four other proteins. The leucine-rich repeat of CCR4 was both necessary and sufficient for interaction with at least two of these factors. We propose that the leucine-rich repeat links CCR4 through its associated factors to its promoter context at ADH2 and other loci where it is required for proper transcriptional regulation.

The growth of the green algaChlorella pyrenoidosa was inhibited by terpene alcohols and the terpene aldehyde citral. The strongest activity was shown by citral. Nerol, geraniol, and citronellol also showed pronounced activity. Strong inhibition was linked to acyclic terpenes containing a primary alcohol or aldehyde function. Inhibition appeared to be taking place through the vapor phase rather than by diffusion through the agar medium from the terpene-treated paper disks used in the system. Inhibition through agar diffusion was shown by certain aged samples of terpene hydrocarbons but not by recently purchased samples.

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